• Description: Niemann–Pick disease type C is caused by NPC1 deficiency, leading to lysosomal cholesterol accumulation. This disrupts lysosomal Ca²⁺ and H⁺ homeostasis, impairs autophagy and mitophagy, promotes mitochondrial dysfunction, reduces ATP production, increases oxidative stress, and drives progressive neurodegeneration.
• Targeting strategy: The exons 2-11 of mouse Npc1 gene were knocked out in B-Npc1 KO mice(C), leading to loss of protein expression.
• Validation: Mouse Npc1 mRNA was exclusively detectable in BALB/cCrSlcNifdc but not in B-Npc1 KO mice(C). Npc1 protein can only be detected in wild-type BALB/cCrSlcNifdc mice but not in homozygous B-Npc1 KO mice(C).
• Application: This B-Npc1 KO mice(C) model is a disease model of Niemann-Pick Disease and can be used in preclinical evaluation of therapeutic candidates (e.g., gene therapies), and exploration of novel treatment strategies for Niemann-Pick Disease.

Gene targeting strategy for B-Npc1 KO mice(C). The exons 2-11 of mouse Npc1 gene were knocked out in B-Npc1 KO mice(C), leading to loss of protein expression.

Strain specific analysis of Npc1 mRNA expression in wild-type BALB/cCrSlcNifdc and B-Npc1 KO mice(C) by RT-PCR. Cerebral cortex RNA was isolated from wild-type BALB/cCrSlcNifdc (+/+) and homozygous B-Npc1 KO mice(C) (-/-), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse Npc1 primers. Mouse Npc1 mRNA was exclusively detectable in BALB/cCrSlcNifdc but not in B-Npc1 KO mice(C).

Western blot analysis of Npc1 protein expression in homozygous B-Npc1 KO mice(C). Various tissue lysates were collected from wild-type BALB/cCrSlcNifdc mice (+/+) and homozygous B-Npc1 KO mice(C) (-/-) (male, 7-week-old), and then analyzed by western blot with anti-Npc1 antibody (Cell Signaling, 33422). 40 μg total protein was loaded for western blotting analysis. Npc1 protein can only be detected in wild-type BALB/cCrSlcNifdc mice but not in homozygous B-Npc1 KO mice(C).